Loading...
HomeMy WebLinkAbout9 Chicken Express 03-84 800 Earl Rudder FWY~w DEVELOPMENT PERMIT PERMIT NO. 04-03-84 Project: CHICKEN EXPRESS COLLl<il STATION FOR AREAS INSIDE THE SPECIAL FLOOD HAZARD AREA RE : CHAPTER 13 OF THE COLLEGE STATION CITY CODE SITE LEGAL DESCRIPTION: LOT 2RE BLK 1 GATEWAY SUBD PH 1 DATE OF ISSUE: 3/22/04 OWNER: GATEWAY FUELS LLC 804 EARL RUDDER FRWY S COLLEGE STATION , TX 77840 TYPE OF DEVELOPMENT: SPECIAL CONDITIONS: SITE ADDRESS: 800 EARL RUDDER FWY S DRAINAGE BASIN: Burton Creek VALID FOR 9 MONTHS CONTRACTOR: Full Development Permit All construction must be in compliance with the approved construction plans All trees required to be protected as part of the landscape plan must be completely barricaded in accordance with Section 7 .5.E., Landscape/Streetscape Plan Requirements of the City's Unified Development Ordinance , prior to any operations of this permit. The cleaning of equipment or materials within the drip line of any tree or group of trees that are protected and required to remain is strictly prohibited . The disposal of any waste material such as, but not limited to , paint, oil , solvents , asphalt , concrete , mortar, or other harmful liquids or materials within the drip line of any tree required to remain is also prohibited. ERSION CONTROL REQUIRED ONSITE AND ALONG TXDOT ROW The Contractor shall take all necessary precautions to prevent silt and debris from leaving the immediate construction site in accordance with the approved erosion control plan as well as the City of College Station Drainage Policy and Design Criteria . If it is determined the prescribed erosion control measures are ineffective to retain all sediment onsite , it is the contractors responsibility to implement measures that will meet City , State and Federal requirements. The Owner and/or Contractor shall assure that all disturbed areas are sodden and establishment of vegetation occurs prior to removal of any silt fencing or hay bales used for temporary erosion control. The Owner and/or Contractor shall also insure that any disturbed vegetation be returned to its original condition , placement and state . The Owner and/or Contractor shall be responsible for any damage to adjacent properties , city streets or infrastructure due to heavy mach inery and/or equipment as well as erosion , siltation or sedimentation resulting from the permitted work. In accordance with Chapter 13 of the Code of Ordinances of the City of College Station , measures shall be taken to insure that debris from construction , erosion , and sedimentation shall not be deposited in city streets , or existing drainage facilities . I hereby grant this permit for development of an area inside the special flood hazard area . All development shall be in accordance with the plans and specifications submitted to and approved by the City Engineer in the development permit application for the above named project and all of the codes and ordinances of the City of College Station that apply . Date I Owner/AgenUContractor Date ul a: . ... w c . RS ,_ Q. en v ... ... c -O t -cu ,_ 2:~ .c (J) • OI u c m .!:::: ~t • OI 2:~ .., ro B ~ . .., ·-L -c 8 e .., ~ Spencer Thompson City of College Station Development Services P.O . Box 9960 rtEVIEWED FOR · ""'''PltAN~E IJC r 2 7 2003 I CUt.LcGE ST A TtON ENGINEERING College Station, Texas 77840 October 20 , 2003 R e : Dra in age Requirements for Congleton Carwa s h, Chicke n Express and Future R estaurant to be located on Lot 2RD Dear Spencer, The purpose of this letter is to discuss the drainage infrastructure required for the proposed Congleton Carwash, to be located on Lot 2RB, Chicken Express , to be located on Lot 2RE , and the future unnamed restaurant, to be located on Lot 2RD of the Gateway Subdivision . The proposed development will heretofore be referred to as the Congleton property. Per the City of College Station Drainage Policy and Design Standards (DPDS), detention is required to store excess volumes of stormwater runoff and discharge it at a rate equal to or less than the pre-development peak flow rate. As is the case with other properties in the Gateway Subdivision , this detention requirement is fulfilled through the use of a regional detention facility, located to the north of the College Station Home Depot. While the runoff from the Congleton property sites will not be discharged into the detention pond, the pond design provides excess stormwater detention for the contributing areas that will compensate for the volume increase on the adjacent properties after their respective development. The drainage calculations , pipe design , and detention pond routing calculations for the Gateway Center are detailed in the Drainage/D etention Report for th e Home Depot (Bury & Partners-SA, Inc., 2002). These calculations include a po st- development runoff coefficient of C=0.85 for drainage sub-basin 7. The drainage design for the Congleton property has a few variations from the original report that have caused an increase in the peak flow for all of the relevant rainfall events. The first of these is that the estimated runoff coefficient used in the Bury & Partners report is C =0.85, lower than the majority of drainage basins within the Gateway subdivision. There is no indication in the report as to why this assumption was made. The actual runoff coefficient for the Congleton property is approximately C=0 .89. In addition, an area calculation discrepanc y was identified for the Congleton property, which is identified as drainage sub-basin 7 in the Bury & Partners drainage report. The Bury & Partners drainage report assumed sub- basin 7 at 2 .5 acres while drainage area calculations performed by Mitchell & Morgan determined the total drainage area for sub -basin as 2 .823 acres . This error resulted in the addition of 0 .323 acres for Lot 2R from the original report. Finally, the Bury & Partners report used TxDOT IDF relationships for Rational Method calculations instead of City of College Station IDF relationships. At the direction of the City of College Station, the drainage design for the Congleton property employs the T xDOT IDF curves in order to maintain consistency with the rest of the Gateway Subdivision. ' -... Because no predevelopment drainage calculations were performed for specifically Lot 2R in the Bury & Partners drainage report, the predevelopment peak flow was calculated using the runoff coefficient C=0.55 and the area (2.823 acres) shown in the drainage area map provided . This includes the adjustment for the additional 0.323 acres mentioned in the previous section . Since the study point for the flow was the junction box for the 66" public storm sewer system , a time of concentration of 14 minutes , equal to that of the total drainage basin at that point, was used to determine a peak intensity of 9.97 in/hr . This resulted in a predevelopment peak discharge of 239.9 cfs at the junction box. This was slightly higher than the predevelopment peak discharge of 238.1 cfs calculated using the Bury & Partners parameters of C=0 .85 and area of 2.50 acres. A postdevelopment peak flow of 244.6 cfs was calculated using a full development runoff coefficient of C=0.89 for Lots 2RB , 2RD , and 2RE and leaving the remainder of Lot 2R unde veloped. Drainage design was not provided for Lots 2RA and 2RC leaving the peak runoff rates the same in both the pre-and postdevelopment drainage calculations for those lots. Drainage analysis indicates a flow increase calculated by Mitchell & Morgan of 4 .7 cfs for sub- basin 7. The Bury & Partners report calculated peak flowrates using both the Rational Method in a spreadsheet and .using StormCAD for the pipe design calculations. This resulted in peak flows at the study point Uunction box) of 245.6 cfs for the Rational Method and 247 .6 cfs for the StormCAD outputs and a noticeable discrepancy. Because Mitchell & Morgan used the Rational Method to perform flow calculations , spreadsheet flow calculations from the Bury & Partners report were used for comparison . The results of the analysis indicate that the postdevelopment peak flowrate does not exceed the design maximum provided by the Bury & Partners report. Exhibit 2 from the Bury & Partners drainage report shows Lot 2R located within the post- development drainage basin DA-lP. Exhibit 3 for this same report further demonstrates that th e lot is part of drainage sub-basin 7 . It is indicated within the Bury & Partners drainage report that the Gateway Subdivision is designed such that drainage area DA-2P (32.5 ac.) is the only drainage area that is discharge into the detention pond. The remainder of the site drains to either the 66" public storm sewer system and discharges into Burton Creek or is drained to the TxDOT culvert under the SH6 west frontage road . Bury & Partners StormCAD outputs provide data indicating that drainage sub-basin 7 is included in the calculations for the public 66" RCP (sp ecified as a 60 " RCP in the report) storm sewer, which is designed to bypass the regional detention pond . As a result of the information provided in the Drainage Report for th e Home D epot, prepared by Bury & Partners , Inc ., the propos ed Congleton property sites have met the dete ntion requirement specified in the College Station DPDS. The storm water runoff from the proposed developments enters the 66" RCP via a 24" RCP connector. A grate inlet will be placed between Lots 2RB and 2RD and sized for the 100-year rainfall event. The water will then be carried through the 88 '-24" RCP connector to the existing junction box on the 66" RCP storm sewer. Ultimately, the resultant flow will be discharged into Burton Creek. The carwash drainage infrastructure, including connection pipes and grate inlet sizes and locations, is detailed in Sheet 1 of the Congleton Carwash construction drawings. In addition, Hydraulic Grade Line calculations were performed for the 66" RCP storm sewer in order to assess the effects of the existing water surface on the proposed inlet. New calculations w ere performed because the Bury & Partners drainage report included the design of a 60" RCP storm sewer that has since been modified to a 66" RCP . The HGL at the proposed Congleton property inlet is approximately 271.65 ft, providing nearly 1.5 feet of clearance between the .. water surface and the proposed top of grate. Peak discharge , pipe sizing, and hydraulic grade calculations have been provided as Appendices A-1 , A-2 and A-3. Review of the stormwater analysis indicates that the drainage design presented in this report accounts for detention and will provide ample conveyance to meet the drainage objectives of the City of College Station Drainage Policy and Design Standards . u have any questions or ~?nunents, please fee l free to contact me. Cc: File Drew Congleton , Owner Frank Mihalopoulos, Del Mar Realty Investors Attachments: Excerpts from Bury & Partners, Inc. Drainage/D etention Report for the Hom e D epot , August 2002 Mitchell & Morgan Drainage Calculations . w cL .... c ta .... OI 41 ... c: o~ :I:~ • OI al.!: • OI "IO ta c: U IO ·-::E c e ~ . w . A. ... --QI .... J:! CV u c: ~~ %~ . " -8 " OCT ~ 7 2DD3 COi.Leu" STATION --~l~EERING Spencer Thompson City of College Station Development Services P.O. Box 9960 College Station, Texas 77840 October 20, 2003 Re: Drainage Requirements for Congleton Carwash, Chicken Express and Future Restaurant to be located on Lot 2RD Dear Spencer, The purpose of this letter is to discuss the drainage infrastructure required for the proposed Congleton Carwash, to be located on Lot 2RB, Chicken Express, to be located on Lot 2RE, and the future unnamed restaurant, to be located on Lot 2RD of the Gateway Subdivision . The proposed development will heretofore be referred to as the Congleton property. Per the City of College Station Drainage Policy and Design Standards (DPDS), detention is required to store excess volumes of stormwater runoff and discharge it at a rate equal to or less than the pre-development peak fl ow rate . As is the case with other properties in the Gateway Subdivision, this detention requirement is fulfilled through the use of a regional detention facility, located to the north of the College Station Home Depot. While the runoff from the Congleton property sites will not be discharged into the detention pond, the pond design provides excess stormwater detention for the contributing areas that will compensate for the volume increase on the adjacent properties after their respective development. The drainage calculations, pipe design, and detention pond routing calculations for the Gateway Center are detailed in the Drainage/Detention Report for the Home Depot (Bury & Partners-SA, Inc ., 2002). These calculations include a post- development runoff coefficient of C=0.85 for drainage sub-basin 7. The drainage design for the Congleton property has a few variations from the original report that have caused an increase in the peak flow for all of the relevant rainfall events . The first of these is that the estimated runoff coefficient used in the Bury & Partners report is C=0.85 , lower than the majority of drainage basins within the Gateway subdivision. There is no indication in the report as to why this assumption was made. The actual runoff coefficient for the Congleton property is approximately C=0.89 . In addition , an area calculation discrepancy was identified for the Congleton property, which is identified as drainage sub-basin 7 in the Bury & Partners drainage report . The Bury & Partners drainage report assumed sub- b asin 7 at 2 .5 acres while drainage area calculations performed by Mitchell & Morgan determined the total drainage area for sub-basin as 2 .823 acres . This error resulted in the addition of OJ23 acres for Lot 2R from the original report. Finally, the Bury & Partners report used TxDOT IDF relationships for Rational Method calculations instead of City of College Station IDF relationships. At the direction of the City of College Station , the drainage design for the Congleton property employs the TxDOT IDF curves in order to maintain consistency with the rest of the Gateway Subdivision . .l Because no predevelopment drainage calculations were performed for specifically Lot 2R in the Bury & Partners drainage report, the predevelopment peak flow was calculated using the runoff coefficient C=0 .55 and the area (2.823 acres) shown in the drainage area map provided. This includes the adjustment for the additional 0 .323 acres mentioned in the previous section . Since the study point for the flow was the junction box for the 66" public storm sewer system, a time of concentration of 14 minutes, equal to that of the total drainage basin at that point, was used to determine a peak intensity of 9.97 in/hr. This resulted in a predevelopment peak discharge of 239.9 cfs at the junction box. This was slightly higher than the predevelopment peak discharge of 238.1 cfs calculated using the Bury & Partners parameters of C=0 .85 and area of 2.50 acres . A postdevelopment peak flow of 244.6 cfs was calculated using a full development runoff coefficient of C=0.89 for Lots 2RB , 2RD, and 2RE and leaving the remainder of Lot 2R undeveloped. Drainage design was not prdvided for Lots 2RA and 2RC leaving the peak runoff rates the same in both the pre-and postdev elopment drainage calculations for those lots. Drainage analysis indicates a flow increase calculated by Mitchell & Morgan of 4.7 cfs for sub- basin 7. The Bury & Partners report calculated peak flowrates using both the Rational Method in a spreadsheet and .using StormCAD for the pipe design calculations. This resulted in peak flows at the study point (junction box) of 245.6 cfs for the Rational Method and 247.6 cfs for the StonnCAD outputs and a noticeable discrepancy. Because Mitchell & Morgan used the Rational I , Method to perform flow calculations, spreadsheet flow calculations from the Bury & Partners report were used for comparison. The results of the analysis indicate that the postdevelopment peak flowrate does not exceed the design maximum provided by the Bury & Partners report. Exhibit 2 from the Bury & Partners drainage report shows Lot 2.R located within the post- development drainage basin DA-lP . Exhibit 3 for this same report further demonstrates that the lot is part of drainage sub-basin 7. It is indicated within the Bury & Partners drainage report that the Gateway Subdivision is designed such hat drainage area DA-2P (32.5 ac.) is the only drainage area that is discharge into the detention pond. The remainder of the site drains to either the 66" public storm sewer system and dis~harges into Burton Creek or is drained to the TxDOT culvert under the SH6 west frontage road . Bury & Partners StohnCAD outputs provide data indicating that drainage sub-basin 7 is included in the calculations for the public 66 " RCP (specified as a 60" RCP in the report) storm sewer, which is designed to bypass the regional detention pond. As a result of the information provided in the Drainage Report for the Home D epot, prepared by Bury & Partners, Inc ., the proposed Congleton property sites have met the detention requirement specified in the College Station DPDS. The storm water runoff from the proposed developments enters the 66" RCP via a 24" RCP connector. A grate inlet will be placed between Lots 2RB and 2.RD and sized for the 100-year rainfall event. The water will then be carried through the 88 '-24" RCP connector to the existing junction box on the 66" RCP storm sewer. Ultimately, the resultant flow will be discharged into Burton Creek. The carwash drainage infrastructure, including connection pipes and grate inlet I sizes and locations, is detailed in Sheet 1 of the Congleton Carwash construction drawings . In addition, Hydraulic Grade Line calculation s were performed for the 66" RCP storm sewer in order to assess the effects of the existing water surface on the proposed inlet. New calculations were performed because the Bury & Partners drainage report included the design of a 60" RCP storm sewer that has since been modified to a 66" RCP. The HGL at the proposed Congleton property inlet is approximately 271.65 ft, pt oviding nearly 1.5 feet of cl earance betwe en the water surface and the proposed top of grate. Peak discharge, pipe sizing, and hydraulic grade calculations have been provided as Appendices A-1, A-2 and A-3. Review of the stormwater analysis indicates that the drainage design presented in this report accounts for detention and will provide ample conveyance to meet the drainage objectives of the City of College Station Drainage Policy and Design Standards. u have any questions or ~?mments, please feel free to contact me. Cc: File Drew Congleton, Owner Frank Mihalopoulos, Del Mar Realty Investors Attachments : Excerpts from Bury & Partners, Inc. Drainage/Detention Report for the Home Depot, August 2002 Mitchell & Morgan Drainage Calculations .. I • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • POST DEVELOPMENT DRAINAGE Overall Drainage Plan The developed Gateway subdivision will provide a detention facility within Lot 9 that will collect the runoff from DA-2P (32 .5 Acres). This drainage area includes Lot 7 which is planned to be developed by Wings & More. The site was designed by Mitchell & Morgan. Onsite detention was waived fo r this site at the time of platting and plan submittal provided detention was provided in the future by the developer of Lot lA. A storm drainage structure will be constructed to convey storm drainage runoff from DA-lE/P to a point north of DA-2P . il'h: etenfro acitity; ized:to::accn:unJ fa the fi.irure ev-elopmen ot::t:o t:2R ano to :t Ol Public Storm Drainage The rational formula was used to calculate the runoff for DA-lP (See Table 1 ). A proposed 60-inch public storm sewer will be constructed within Lots l I and 2R to intercept the flow from DA-IP and convey the flow for the 2-I OOyr storms though the site . A 6'x6' junction box will connect the proposed 60" storm sewer to existing 48", 30'', and 18 " storm sewer pipes . The 60" storm sewer will collect storm drain runoff from three additional .points . StormCAD was used to model the proposed storm drainage system . Due to elevation constraints the storm drainage pipe was placed at the preferred frictional slope . (See Appendix 2 for StormCAD Pipe Report) . On-Site Storm Drainage System The on-site post-development drainage areas were calculated using the rational method (See Table 1) . The On-site Drainage Master Plan consists of I 8 separate drainage areas and two separate drainag e systems that convey the on-site drainage to the private detention pond (See Exhibit 3) . Western Private Storm Sewer Only a portion of the western drainage system will presently be constructed with the development df Lot I l . The western system was designed for I 0-yr ultimate development and analyzed using StormCAD (See Appendix 3). The system will stub out into Lot IA with area inlets . The remaind er of the western system will be built when Lot IA is developed. The future storm system will collect the remainder of the storm w-ater flow from Lot IA and a portion of the 60' private access easement locat ed along the western property line of Lot IA. Inlets are sized by drainage area collected at each inl et based on Table I and inl et calculations (Appendix 3) . Eastern Private Storm Sewer The eastern storm drainage system will be constructed within Lot I l. This eastern system was designed for the IO -yr ultimate development and analyzed using StormCAD (See Appendix 3) . 2 ~----------------BU R Y +PARTNER S ------------------' ••••••e~~ •••••• •••• ,.,,,,,,,,,,, ••• ~ TABLE 1: Rational Formula Drainage Area Calculations -< cj cj ;;:: ;;:: ;;:: > > < w < < w 0:: 0 0 g~ 0:: :I: 0:: 0:: < ...J ...J ;;:: ~ < < I-LL LL LL -0 w I-w ti) z c (.) ;;:: (.!) ;;:: w w :::::> w c c zo ...J ...J wz ~~ 0:: 0 z z LL LL ~ (.!) < LL U :5 ill ti) w u < 5 <:I: < 0:: :I: 0:: -:ii: ...J I-...J LL LL ...J I-...J w I-w (.) :ii: u u z < 0:: 0 LL 0:: (.!) 0:: ...J 0:: >: ~ (.!) ~o 0:: ;;:: 0:: 0 c_j I-~ w 0 I-a.. zw Wz w ...J w (.!) :::::> z :::::> ill 00 0 ...J ...J w 0 I() 0 0 0 0 :::::> 0 >w >< >> I-...J I-w < Cl) N I() 0 ~ I() N 0 I() 0 ~ c I-:ii: 0:: (.) 0 ...J 0 LL O< (.!) ~ (.!) > ti) LL en > (.) ::> ~ 0 !!! 0 :::: 0 ~ 0 !!! 0 :::: 0 No. Ac. % ft. ft. ft. ft/s ft. ft/s min min In/Hr cfs In/Hr cfs In/Hr cfs In/Hr cfs In/Hr cfs In/Hr cfs 1E 37.5 65.0 0.60 335 1.0 2.0 1700 2.8 300 6.0 14.0 14.0 5.4 121.1 6.6 148.4 7.4 167.3 8.5 191.4 9.6 216.8 10.1 226.2 2E 39.6 0.0 0.55 420 37.0 4.3 0 0 0 0 1.6 10.0 6.3 137.8 7.7 167.5 8.6 188.1 9.9 214.8 11.1 242.8 11.6 253.5 2P 32.5 9.0.0 0.90 325 2.0 1.0 400.0 4.8 1850 6.0 12.0 12.0 5.8 170.3 7.1 207.9 8.0 233.9 9.1 267.4 10.3 302.5 10.8 315.7 4E 5 8 0.55 750 3 2 0 0 0 0 6.3 10.0 6.3 17.4 7.7 21.2 8.6 23.7 9.9 27".1 11.1 30.7 11.6 32.0 SP 2.3 10 0.55 600 3 2 0 0 150 6 5.4 10.0 6.3 8.0 7.7 9.7 8.6 10.9 9.9 12.5 11.1 14.1 11.6 14.7 Storm Drainage Area Calculations 1 11.0 90 0.90 350 A 5 510 3 1750 6 8.9 10.0 6.3 62.7 7.7 76.2 8.6 85.6 9.9 97.7 11.1 110.5 11.6 115.3 2 6.09 90 0.90 300 14 13 360 13 0 0 0.8 10.0 6.3 34.7 7.7 42.2 8.6 47.3 9.9 54.1 11.1 61.1 11.6 63.8 3 0.45 100 0.90 120 1.5 4 0 0 0 0 0.5 10.0 6.3 2.6 7.7 3.1 8.6 3.5 9.9 4.0 11.1 4.5 11.6 4.7 4 3.13 90 0.90 50 1 2 600 8 0 0 1.7 10.0 6.3 17.8 7.7 21.7 8.6 24.3 9.9 27.8 11.1 31.4 11.6 32.8 5 1.87 90 0.90 300 5 6 0 0 0 0 0.8 10.0 6.3 10.6 7.7 12.9 8.6 14.5 9.9 16.6 11.1 18.8 11.6 19.6 6 1.05 90 0.90 150 3 6 0 0 0 0 0.4 10.0 6.3 6.0 7.7 7.3 8.6 8.2 9.9 9.3 11.1 10.5 11.6 11.0 c:::=-7.. -2$ _8_5 :_o_.85 -300 f-~ -6 0 ~ 0 _O -o.8 10.0 6.3 13.4 7.7 16.3 8.6 18.3 9.9 21.0 ·11.1 ~23.7 11.6 24.7\ 8 0.75 90 0.90 240 2 6 0 0 0 0 0.7 10.0 6.3 4.3 7.7 5.2 8.6 5.8 9.9 6.7 11.1 7.5 11.6 7.9 9 1.44 90 0.90 140 2 6 0 0 0 0 0.4 10.0 6.3 8.2 7.7 10.0 8.6 11.2 9.9 12.8 11.1 14.4 11.6 15.1 10 1.05 90 0.90 360 3.5 6 0 0 0 0 1.0 10.0 6.3 6.0 7.7 7.3 8.6 8.2 9.9 9.3 11.1 10.5 11.6 11.0 11 0.49 90 0.90 175 3 6 0 0 0 0 0.5 10.0 6.3 2.8 7.7 3.4 8.6 3.8 9.9 4.3 11.1 4.9 11.6 5.1 12 0.76 100 0.90 200 1.5 6 0 0 0 0 0.6 10.0 6.3 4.3 7.7 5.3 8.6 5.9 9.9 6.7 11.1 7.6 11.6 8.0 13 1.78 90 0.90 240 2 6 0 0 0 0 0.7 10.0 6.3 10.1 7.7 12.3 8.6 13.8 9.9 15.8 11 .1 17.9 11.6 18.6 14 0.29 90 0.90 240 2 6 0 0 0 0 0.7 10.0 6.3 1.7 7.7 2.0 8.6 2.3 9.9 2.6 11.1 2.9 11.6 3.0 15 0.3 100 0.90 180 2 6 0 0 0 0 0.5 10.0 6.3 1.7 7.7 2.1 8.6 2.3 9.9 2.7 11.1 3.0 11.6 3.1 16 0.09 100 0.90 80 1.5 6 0 0 0 0 0.2 10.0 6.3 0.5 7.7 0.6 8.6 0.7 9.9 0.8 11.1 0.9 11.6 0.9 17 1.18 100 0.90 240 2 6 0 0 0 0 0.7 10.0 6.3 6.7 7.7 8.2 8.6 9.2 9.9 10.5 11.1 11.8 11.6 12.4 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~BURY+PARTNERS~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~J Label Upstream Upstream Inlet Inlet Area CA (acres) (acres) P-1 37 .50 22 .50 1r p ";,: ;,:.50 2 .12 P -5 0.49 0.44 P -6 1 .78 1.60 P-4 0 .29 0 .26 Title : HD-College Station j :\048\030\public drain .stm 09/03/02 09:30 :55 AM ••• Upstream Calculated System Total Length System CA Intensity System (ft) (acres) (in/hr) Flow (cfs) 22 .50 10.05 228 .01 166.80 2 ~63--9 .97 24 .5]: 501.00 25.07 9 .76 246.67 127.72 26.67 9 .71 261 .03 200 .30 26.93 9.63 261 .51 28 .00 • Scenario: Base Pipe Report Constructed Section Slope Size (ft/ft) 0 .005036 60 inch 0 .004990 60 incn 0 .005011 60 inch 0 .004993 60 inch 0 .005000 60inch Mannings Full n Capacity (cfs) 0 .014 171 .61 0 .014 '1 70.83 0 .014 171 .18 0 .014 170.87 0.014 171.00 IOO~fl. SforVV> Bury & Partners •••••••••••••• Upstream Downstream Hydraulic Hydraulic Invert Invert Grade Grade Elevation Elevation Line Out Line In (ft) (ft) (ft) (ft) 265 .29 264.45 274 .18 275 .66 ,_264.45 26 .9!> ~26 !r.93 2 7n8" 261 .95 261 .31 267 .60 268.93 261 .31 260.31 265 .26 267 .60 260.31 260 .17 264.66 265 .26 © Haestad Methods , Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Project Engineer: BPI User StormCAD v4 .1.1 (4 .2014] Page 1 of 1 w . A. . ... II.I c . fa .... A. e., ~ 0€ -%~ ~ .... • OI ·-~ al .E • OI :E~ "" l'O l'J~ • .., ·-~ -c 8 e .., ~ Spencer Thompson City of College Station Development Services P.O . Box 9960 College Station, Texas 77840 REVIEWED FOR ~O .. PI '~NCE OCT 2 7 2003 COLLEGt: STATION ENGINEERING October 20, 2003 Re: Drainage Requirements for Congleton Carwash, Chicken Express and Future Restaurant to be located on Lot 2RD Dear Spencer, The purpose of this letter is to discuss the drainage infrastructure required for the proposed Congleton Carwash, to be located on Lot 2RB, Chicken Express, to be located on Lot 2RE, and the future unnamed restaurant, to be located on Lot 2RD of the Gateway Subdivision. The proposed development will heretofore be referred to as the Congleton property. Per the City of College Station Drainage Policy and Design Standards (DPDS), detention is required to store excess volumes of stormwater runoff and discharge it at a rate equal to or less than the pre-development peak flow rate. As is the case with other properties in the Gateway Subdivision, this detention requirement is fulfilled through the use of a regional detention facility , located to the north of the College Station Home Depot. While the runoff from the Congleton property sites will not be discharged into the detention pond, the pond design provides excess stormwater detention for the contributing areas that will compensate for the volume increase on the adjacent properties after their respective development. The drainage calculations, pipe design, and detention pond routing calculations for the Gateway Center are detailed in the Drainage/Detention Report for the Home Depot (Bury & Partners-SA, Inc., 2002). These calculations include a post- development runoff coefficient ofC=0.85 for drainage sub-basin 7. The drainage design for the Congleton property has a few variations from the original report that have caused an increase in the peak flow for all of the relevant rainfall events. The first of these is that the estimated runoff coefficient used in the Bury & Partners report is C=0.85, lower than the majority of drainage basins within the Gateway subdivision. There is no indication in the report as to why this assumption was made . The actual runoff coefficient for the Congleton property is approximately C=0 .89. In addition, an area calculation discrepancy was identified for the Congleton property, which is identified as drainage sub-basin 7 in the Bury & Partners drainage report . The Bury & P artners drainage report assumed sub- basin 7 at 2.5 acres while drainage area calculations performed by Mitchell & Morgan determined the total drainage area for sub -basin as 2 .823 acres . This error resulted in the addition of OJ23 acres for Lot 2R from the original report. Finally, the Bury & Partners report used TxDOT IDF relationships for Rational Method calculations instead of City of College Station IDF relationships. At the direction of the City of College Station, the drainage design for the Congleton property employs the TxDOT IDF curves in order to maintain consistency with the rest of the Gateway Subdivision . Because no predevelopment drainage calculations were performed for specifically Lot 2R in th¢ Bury & Partners drainage report, the predevelopment peak flow was calculated using the runoff coefficient C=0.55 and the area (2 .823 acres) shown in the drainage area map provided . This includes the adjustment for the additional 0 .323 acres mentioned in the previous section . Since the study point for the flow was the junction box for the 66" public storm sewer system, a time of concentration of 14 minutes, equal to that of the total drainage basin at that point, was used to determine a peak intensity of 9.97 in/hr. This resulted in a predevelopment peak discharge of 239 .9 cfs at the junction box . This was slightly higher than the predevelopment peak discharge of238 .l cfs calculated using the Bury & Partners parameters ofC=0.85 and area of2.50 acres . A postdevelopment peak flow of 244 .6 cfs was calculated using a full development runoff coefficient of C=0.89 for Lots 2RB, 2RD, and 2RE and leaving the remainder of Lot 2R undeveloped. Drainage design was not prdvided for Lots 2RA and 2RC leaving the peak runoff rates the same in both the pre-and postdevelopment drainage calculations for those lots. Drainage analysis indicates a flow increase calculated by Mitchell & Morgan of 4 .7 cfs for sub- basin 7. The Bury & Partners report calculated peak flowrates using both the Rational Method in a spreadsheet and.using StormCAD for the pipe design calculations. This resulted in peak flow s at the study point Uunction box) of 245.6 cfs for the Rational Method and 247.6 cfs for the StormCAD outputs and a noticeable discre~ancy. Because MitChell & Morgan used the Ration ~l I . Method to perform flow calculations, spreadsheet flow calculations from the Bury & Partners report were used for comparison. The results of the analysis indicate that the postdevelopment peak flowrate does not exceed the design maximum provided by the Bury & Partners report. Exhibit 2 from the Bury & Partners drainage report shows Lot 2R located within the post- development drainage basin DA-IP. Exhibit 3 for this same report further demonstrates that the lot is part of drainage sub-basin 7. It is indicated within the Bury & Partners drainage report that the Gateway Subdivision is designed such that drainage area DA-2P (32 .5 ac.) is the only drainage area that is discharge into the detention pond. The remainder of the site drains to either the 66" public storm sewer system and distharges into Burton Creek or is drained to the TxDOT culvert under the SH6 west frontage road. Bury & Partners StohnCAD outputs provide data indicating that drainage sub-basin 7 is included in the calculations for the public 66" RCP (specified as a 60" RCP in the report) storm sewer, which is designed to bypass the regional detention pond. As a result of the information provided in the Drainage Report for the Home Depot, prepared by Bury & Partners, Inc ., the proposed Congleton property sites have met the detention requirement specified in the College Station DPDS. The stormwater runoff from the proposed developments enters the 66" RCP via a 24" RCP connector. A grate inlet will be placed between Lots 2RB and 2RD and sized for the 100-year rainfall event. The water will then be carri~d through the 88 '-24" RCP connector to the existing junction box on the 66" RCP storm sewer. Ultimately, the resultant flow will be discharged into Burton Creek. The carwash drainage infra ~tructure, including connection pipes and grate inlet sizes and locations, is detailed in Sheet 1 of the Congleton Carwash construction drawings. In addition, Hydraulic Grade Line calculations were performed for the 66" RCP storm sewer in order to assess the effects of the existing water surface on the proposed inlet. New calculations were performed because the Bury & Partners drainage report ineJuded the design of a 60 " RCP storm sewer that has since been modified to a 66" RCP. The HGL at the proposed Congleton property inlet is approximately 271.65 ft , pt oviding nearly 1.5 feet of clearance betwe en the water surface and the proposed top of grate. Peak discharge, pipe sizing, and hydraulic grade calculations have been provided as Appendices A-1, A-2 and A-3 . Review of the stormwater analysis indicates that the drainage design presented in this report accounts for detention and will provide ample conveyance to meet the drainage objectives of the City of College Station Drainage Policy and Design Standards. u have any questions or comments, please feel free to contact me. ~ I • • Cc : File Drew Congleton, Owner Frank Mihalopoulos, Del Mar Realty Investors Attachments : Excerpts from Bury & Partners, Inc . Drainage/Detention Report for the Home Depot, August 2002 Mitchell & Morgan Drainage Calculations POST DEVELOPMENT DRAINAGE Overall Drainage Plan The developed Gateway subdivision will provide a detention facility within Lot 9 that will collect the runoff from DA-2P (32.5 Acres). This drainage area includes Lot 7 which is planned to be developed by Wings & More. The site was designed by Mitchell & Morgan. Onsite detention was waived for this site at the time of platting and plan submittal provided detention was provided in the future by the developer of Lot lA. A storm drainage structure will be constructed to convey storm drainage runoff from DA-lEJP to a point north of DA-2P . 411~ ention faci licy 6een siZea to account fo r: the tm:e::-de~etopm--ent of:t:Dt 2R arrd t.ot 10. Public Storm Drainage The rational formula was used to calculate the runoff for DA-lP (See Table 1). A proposed 60-inch public storm sewer will be constructed within Lots 11 and 2R to intercept the flow from DA-lP and convey the flow for the 2-lOOyr storms though the site. A 6'x6' junction box will connect the proposed 60" storm sewer to existing 48", 30", and 18" storm sewer pipes. The 60" storm sewer will collect storm drain runoff from three additional points . StormCAD was used to model the proposed storm drainage system . Due to elevation coristraints the storm drainage pipe was placed at the preferred frictional slope. (S ee Appendix 2 for StormCAD Pipe Report). On-Site Storm Drainage System The on-site post-development drainage areas were calculated using the rational method (See Table 1). The On-site Drainage Master Plan consists of 18 separate drainage areas and two separate drainage systems that convey the on-site drainage to the private detention pond (See Exhibit 3). Western Private Storm Sewer Only a portion of the western drainage system will presently be constructed with the development of Lot 11. The western system was designed for 10-yr ultimate development and analyzed using StormCAD (See Appendix 3). The system will stub out into Lot lA with area inlets. The remainder of the western system will be built when Lot lA is developed. The future storm system will collect the remainder of the storm water flow from Lot lA and a portion of the 60' private access easement located along the western property line of Lot lA. Inlets are sized by drainage area collected at each inlet based on Table 1 and inlet calculations (Appendix 3). Eastern Private Storm Sewer The eastern storm drainage system will be constructed within Lot 11. This eastern system was designed for the 10-yr ultimate development and analyzed using StormCAD (See Appendix 3). 2 '-------------------BUA Y +PAATNEA S ---------------~ •••••• •e•••• • ····················~ T E 1: Rational F la D . Area Calculaf <( ci ci ~ ~ ~ > > <( w <( <( w ex: 0 0 g~ ex: :I: ex: ex: <( I-..J ..J ~ ~ w I-w <( <( "' LL LL LL -0 0 ~ z cu :!: (!) w w ::::> w c c z3 ..J ..J wz ~~ (!) ex: 0 LL U z z LL LL ~ "' w CJ <( <( > <( :I: <( :5 w 0::: :I: 0::: -~ ..J I-..J LL LL ..J I-..J w I-WU ~u CJ z <( 0::: 0 LL 0::: (!) 0::: ..J 0::: >: ~ (!) ~o 0::: ~ 0::: 0 u I-~ w 0 I-0. zw wz w ..J w (!) ::::> z ::::> u1 00 0 ..J ..J w 0 It'> 0 0 0 0 ::::> 0 >w > <( >> I-..J I-w <( "' N I() 0 ..... I() N 0 It'> 0 ..... c I-~ ex: u 0 ..J 0 LL 0 <( (!) ~ (!) > U) LL "' > u ::::> !::! 0 !!? 0 ::::: 0 !::! 0 !!? 0 ::::: 0 No. Ac. % ft. ft. ft. ft/s ft. ft/s min min In/Hr cfs In/Hr cfs In/Hr cfs In/Hr cfs In/Hr cfs In/Hr cfs 1E 37.5 65.0 0.60 335 1.0 2.0 1700 2.8 300 6.0 14.0 14.0 5.4 121.1 6.6 148.4 7.4 167.3 8.5 191.4 9.6 216.8 10.1 226.2 2E 39.6 0.0 0.55 420 37.0 4.3 0 0 0 0 1.6 10.0 6.3 137.8 7.7 167.5 8.6 188.1 9.9 214.8 11.1 242.8 11.6 253.5 2P 32.5 90.0 0.90 325 2.0 1.0 400.0 4.8 1850 6.0 12.0 12.0 5.8 170.3 7.1 207.9 8.0 233.9 9.1 267.4 10.3 302.5 10.8 315.7 4E 5 8 0.55 750 3 2 0 0 0 0 6.3 10.0 6.3 17.4 7.7 21.2 8.6 23.7 9.9 27: 1 11.1 30.7 11.6 32.0 5P 2.3 10 0.55 600 3 2 0 0 150 6 5.4 10.0 6.3 8.0 7.7 9.7 8.6 10.9 9.9 12.5 11.1 14.1 11.6 14.7 Storm Drainage Area Calculations 1 11.0 90 0.90 350 4 5 510 3 1750 6 8.9 10.0 6.3 62.7 7.7 76.2 8.6 85.6 9.9 97.7 11.1 110.5 11.6 115.3 2 6.09 90 0.90 300 14 13 360 13 0 0 0.8 10.0 6.3 34.7 7J 42.2 8.6 47.3 9.9 54.1 11.1 61.1 11.6 63.8 3 0.45 100 0.90 120 1.5 4 0 0 0 0 0.5 10.0 6.3 2.6 7.7 3.1 8.6 3.5 9.9 4.0 11.1 4.5 11.6 4.7 4 3.13 90 0.90 50 1 2 600 8 0 0 1.7 10.0 6.3 17.8 7.7 21.7 8.6 24.3 9.9 27.8 11.1 31.4 11.6 32.8 5 1.87 90 0.90 300 5 6 0 0 0 0 0.8 10.0 6.3 10.6 7.7 12.9 8.6 14.5 9.9 16.6 11.1 18.8 11.6 19.6 6 1.05 90 0.90 150 3 6 0 0 0 0 0.4 10.0 6.3 6.0 7.7 7.3 8.6 8.2 9.9 9.3 11.1 10.5 11.6 11.0 .. '· -2:"5--ff5: o:s-s: ~OD: 4:~6 o~ ff ff_O ~a.a_ tO.O 6_._3 13.4 7_r 16_.3 8.6 18.3 ~9.9_ 2j.0 u:-t :23.l 11.6 24"'."7' 8 0.75 90 0.90 240 2 6 0 0 0 0 0.7 10.0 6.3 4.3 7.7 5.2 8.6 5.8 9.9 6.7 11.1 7.5 11.6 7.9 9 1.44 90 0.90 140 2 6 0 0 0 0 0.4 10.0 6.3 8.2 7.7 10.0 8.6 11.2 9.9 12.8 11.1 14.4 11.6 15.1 10 1.05 90 0.90 360 3.5 6 0 0 0 0 1.0 10.0 6.3 6.0 7.7 7.3 8.6 8.2 9.9 9.3 11.1 10.5 11.6 11.0 11 0.49 90 0.90 175 3 6 0 0 0 0 0.5 10.0 6.3 2.8 7.7 3.4 8.6 3.8 9.9 4.3 11.1 4.9 11.6 5.1 12 0.76 100 0.90 200 1.5 6 0 0 0 0 0.6 10.0 6.3 4.3 7.7 5.3 8.6 5.9 9.9 6.7 11.1 7.6 11.6 8.0 13 1.78 90 0.90 240 2 6 0 0 0 0 0.7 10.0 6.3 10.1 7.7 12.3 8.6 13.8 9.9 15.8 11.1 17.9 11.6 18.6 14 0.29 90 0.90 240 2 6 0 0 0 0 0.7 10.0 6.3 1.7 7.7 2.0 8.6 2.3 9.9 2.6 11.1 2.9 11.6 3.0 15 0.3 100 0.90 180 2 6 0 0 0 0 0.5 10.0 6.3 1.7 7.7 2.1 8.6 2.3 9.9 2.7 11.1 3.0 11.6 3.1 16 0.09 100 0.90 80 1.5 6 0 0 0 0 0.2 10.0 6.3 0.5 7.7 0.6 8.6 0.7 9.9 0.8 11.1 0.9 11.6 0.9 17 1.18 100 0.90 240 2 6 0 0 0 0 0.7 10.0 6.3 6.7 7.7 8.2 8.6 9.2 9.9 10.5 11.1 11.8 11.6 12.4 '--~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~BURY+PARTNERS~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Labe l Upstream Upstream Inlet Inlet Are a CA (acres) (acres ) P-1 37 .50 22 .50 ( e-2--2 .50 .<:.12 P-5 0.49 0.44 P-6 1 .7 8 1 .60 P-4 0 .29 0 .26 T itle : HD-College Station j :\048 \030\publ ic drain .stm 09 /03 /02 09 :30 :55 AM •• Upstream Calculated System Total Length System CA Intensity System (ft) (acres) (in/hr) Flow (cfs ) 22.50 10.05 228 .01 166.80 ,_ 6_3 =_9 .97 2'17 .58 501 .00 25 .07 9.76 246 .67 127 .72 26.67 9 .71 261 .03 200 .30 26 .93 9 .63 261 .51 28 .00 • Scenario: Base Pipe Report Constructed Section Slope Size (ft/ft) 0 .005036 60inch ,_ 0 .00'1990 60incH 0 .005011 60 inch 0 .004993 60inch 0 .005000 60inch Mann ings Full n Capacity (cfs) 0 .014 171 .61 -o .Ot 4 170.83 0 .014 171.18 0.014 170 .87 0 .014 171 .00 /Oo ~fl. S To rVV> Bury & Partners •••••••••••••• Upstream Downstream Hydraulic Hydraulic Invert Invert Grade Grade Elevation Elevation Line Out Line In (ft) (ft) (ft ) (ft) 265 .29 264.45 274 .18 275 .66 264.45 ,61 .95 i--268.93 1-274 18 - 261.95 261 .31 267 .60 268 .9 3 261 .31 260 .31 265 .26 267 .60 260.31 260 .17 264 .66 265 .26 © Haestad Method s , Inc. 37 Brookside Road Waterbury , CT 06708 USA +1-203-755-1666 Project Engineer: BPI User StormCAD v4.1 .1 [4 .2014] Page 1 of 1 c( ~ ~ w 0 0 0 D:: w ...J ...J c( c( a.. u. u. w w 0 I-0 0 (!) D:: ...J ...J z c( z z c( c( w c( w u c( :c c( ...J > D:: :::'!: ...J ...J I-...J z c( w w w c( D:: (!) D:: ...J < I-0 z > I-Wz w ...J D:: 0 z w c( 0 >w > c( 0 I-:::> (!) a.. I-0 ...J 0 u. NO. AC. 0.55 0.6 0.95 ft. ft. JB1 0.00 0.00 0.00 0.00 0.00 0.0 0.0 JB2 37.50 0.00 37.50 0.00 22.50 335.0 1.0 EDA-1 1.90 1.90 0.00 0.00 1.05 0.0 0.0 EDA-2 1.30 1.30 0.00 0.00 0.71 0.0 0.0 PDA-1A 0.40 0.40 0.00 0.00 0.22 0.0 0.0 PDA-18 1.51 0.00 0.33 1.19 1.32 135.0 2.0 PDA-2 1.30 1.30 0.00 0.00 0.71 0.0 0.0 Exhibit A-1 Rational Formula Drainage Area Calculations CHICKEN EXPRESS ~ ~ 0 0 ...J ...J u. u. >-D:: :c D:: I-u w I-w u I-u I-(!) I-...J 0 I-I-z I-...J ...J ..!:! w :::> w :::> c( w Ill (/) N ll) (!) ...J (!) u. > u :::> !::! 0 !!? 0 ft. ft. ft/s min min In/Hr cfs In/Hr cfs 0.0 0.0 10.4 0.0 10 6.33 0.0 7.7 0.0 1700.0 2.8 2.4 14.0 14 5.38 121.1 6.6 148.4 389.0 8.5 2.9 2.2 10 6.33 6.6 7.7 8.0 315.5 9.0 3.3 1.6 10 6.33 4.5 7.7 5.5 265.5 11.0 4.0 1.1 10 6.33 1.4 7.7 1.7 120.0 3.3 1.3 3.2 10 6.33 8.4 7.7 10.2 315.5 9.0 3.3 1.6 10 6.33 4.5 7.7 5.5 •• Drainage Area JB2 includes areas identified as EDA-3 and PDA-3 per the Bury & Partners, Inc. Drainage Report 0 ll) 0 ...-ll) N :!: 0 !::! 0 In/Hr cfs In/Hr cfs 8.6 0.0 9.9 0.0 7.4 167.3 8.5 191.5 8.6 9.0 9.9 10.3 8.6 6.2 9.9 7.0 8.6 1.9 9.9 2.2 8.6 11.4 9.9 13.1 8.6 6.2 9.9 7.0 0 !!? In/Hr 11.1 9.6 11.1 11.1 11.1 11.1 11.1 0 0 0 0 ll) 0 ...-0 :!: 0 cfs In/Hr cfs 0.0 11.6 0.0 216.8 10.1 226.2 11.7 11.6 12.2 8.0 11.6 8.3 2.5 11.6 2.6 14.8 11.6 15.4 8.0 11.6 8.3 10/16/2003 0337-Drainage.xls Exhibit A-1 # 0 :z: Emo ~ ...:i :z: -JB1 JB2 PDA-1A PDA-18 PDA-2 # Emo ~ ...:i :z: -0 Emo STPT2 JB1 STPT1 JB1 JB1 Ac. ~ u ...:i ~ Emo 0 Emo 24.54 22.50 0.22 1.32 0.71 (.J Emo min 14.3 14.0 10.0 10.0 10.0 *Includes 25% Flow Increase for pipe sizes <27" dia. yr a I. 0 -r:FJ = .~Jl "' ~ Q 100 100 100 100 100 "'O ~ ~ 0 --= ~ . ...., = "'O OJ) ~ ·-= :l ;;;;J Q cfs 244.6 226.2 2.6 15.4 8.3 ••See Plan & Profile for pipe slope used (Pipe slope >or= Friction slope) Exhibit A-2 Pipe Size Calculations CHICKEN EXPRESS ·l< ~ 0 "'O ~ ~ -= "' OJ) = ·-. ...., "' "'O ~ ~Q <24" cfs 244.6 226.2 3.2 19.3 10.4 # "' ~ .e-~ ...... 0 0 :z: 1 1 1 1 ~ Q. ·-~ I. ~ ~ ~ 0 ~ <24" cfs 244.6 226.2 3.2 19.3 10.4 = ·l< 0 ·l< ·-~ ~ Q. ·-0 I. -~ r:FJ O/o 0.61 0.52 0.11 0.84 0.24 " ~ N -r:FJ 66 66 18 24 24 fps ~ Emo -u 0 ...:i ~ > 10.3 9.5 1.8 6.1 3.3 ·l< ~ ·-(.J ~ Q. ~ u cfs 244.5 226.1 3.2 19.3 10.4 ::r: Emo "" :z: ~ ...:i 40 152 67 88 9 ~ s ~ ~ ;;.. ~ I. Emo min 0.06 0.27 0.61 0.24 0.04 "'O = ~ @' (.J i;... min 14.33 14.27 10.61 10.24 10.04 10/16/2003 0337-Drainage.xls Exhibit A-2 I P-4 100 263 .61 66 P-6 100 263 .13 66 P-5 100 248 .77 66 P-2 100 249 .68 66 P-1 100 228.01 66 HGL at the proposed connection at ·---~ !Junction Box (JB1) I PDA-18 JB1 100 19.26 24 • Includes 25 % Flow Increase for pipe sizes <27" dia. ** See Plan & Profile for pipe slope used (Pipe slope >or= Friction slope) Exhibit A-3 Hydraulic Grade Calculations CHICKEN EXPRESS 28 .0 200 .3 127 .7 501 .0 166 .8 501 .0 88 .0 0 .014 0 .014 0.014 0 .014 0.014 0 .014 c "' ·e.o .:: c c ~ ~ 0 .014 23 .76 1.38 23 .76 1.38 23 .76 1.38 23 .76 1.38 23 .76 1.38 0 .00 0.00 3.14 0.50 *** Design flow column includes the 2 .1 cfs increase specifi ed in the attached letter 11 .10 0 .00711 11 .08 0 .00708 10.47 0.00633 10.51 0.00638 9.60 0.00532 10 .51 0 .00638 6 .13 0 .00836 0 c ~ 0.19 264 .66 265.05 --+----+-----II 0.0 265 .05 266.47 0.0 266.47 267.28 0.0 267 .28 270.47 0.0 270 .47 271 .36 0 .0 0.50 267 .28 270.47 270 .97 271 .71 10/16/2003 0337-Drainage .xls Exhibit A-3 t • • • • ' ' ~ ' ' ' ' ' ' ' • • • • • ' ' ' ' • ' ' ' ' ' ' ' ' ' ' ' POST DEVELOPMENT DRAINAGE Overall Drainage Plan The developed Gateway subdivision will provide a detention facility within Lot 9 that will collect the runoff from DA-2P (32 .5 Acres). This drainage area includes Lot 7 which is planned to be developed by Wings & More. The site was designed by Mitchell & Morgan. Onsite detention was waived for this site at the time of platting and plan submittal provided detention was provided in the future by the developer of Lot IA. A storm drainage structure will be constructed to convey storm drainage runoff from DA-IE/P to a point north of DA-2P . he detenfon facilt has been sizecl to account ror lht;' u ut·~-ue-velopmen o b'O 2R and'bO 10 . Public Storm Drainage The rational formula was used to calculate the runoff for DA-IP (See Table I). A proposed 60-inch public storm sewer will be constructed within Lots I I and 2R to intercept the flow from DA-IP and convey the flow for the 2-1 OOyr storms though the site. A 6'x6 ' junction box will connect the proposed 60" storm sewer to existing 48", 30'', and I8" storm sewer pipes. The 60" storm sewer will collect storm drain runoff from three additional .points. StormCAD was used to model the proposed storm drainage system . Due to elevation constraints the storm drainage pipe was placed at the preferred frictional slope. (See Appendix 2 for StormCAD Pipe Report). On-Site Storm Drainage System The on-site post-development drainage areas were calculated using the rational method (See Table 1) . The On-site Drainage Master Plan consists of I8 separate drainage areas and two separate drainage systems that convey the on-site drainage to the private detention pond (See Exhibit 3) . W este rn Private Storm Sewer Only a portion of the western drainage system will presently be constructed with the development of Lot 11. The western system was designed for 10-yr ultimate development and analyzed using StormCAD (See Appendix 3). The system will stub out into Lot lA with area inlets . The remainder of the western system will be built when Lot lA is developed. The future storm system will collect the remainder of the storm viater flow from Lot lA and a portion of the 60' private access easement locat ed along the western property line of Lot IA. Wets are sized by drainage area collected at each inl e t based on Table 1 and inlet calculations (Appendix 3). Eastern Private Storm Sewer The eastern storm drainage system will be constructed within Lot I I. This eastern system was designed for the 10 -yr ultimate development and analyzed using StormCAD (See Appendix 3). 2 '------------------BURY+ PARTNER S ----------------~ •• ., . --·· •••••• • ••••••••••••••••••••• 1 -<{ 0 0 3: 3: 3: > > <{ w < < w 0::: 0 0 g~ 0::: :I: 0::: 0::: <{ I-..J ..J 3: ~ w I-w < <{ tJ) LL LL LL -0 3: w :::::> z Cl Cl Cl u ..J ..J :;: (!) w c::: 0 w z z z9 LL LL ~ wz ~~ (!) LL U tJ) w (,) <{ <{ 5 <t:I: 5 5w 0::: :I: 0:::-:e ..J I-..J LL -..J I-w I-WU :::!! u (,) z <{ 0::: 0 tt 0::: (!) 0::: ..J 0::: >: ~ (!) ~o 0::: 3: 0::: 0 cJ I-~ w 0 I-c.. zw wz w ..J w (!) :::::> z :::::> ~ 00 0 ..J ..J w 0 in 0 0 0 0 ~ :::::> 0 >w >< >> (!) ~ I-..J I-w < tJ) N in 0 ..... in N 0 in 0 ..... Cl I-c::: u 0 ..J 0 LL O<t (!) > tJ) LL tJ) > u :::::> !::! 0 !!? 0 ..... 0 N 0 &() 0 ..... 0 No. Ac. % ft. ft. ft. ft/s ft. ft/s min min In/Hr cfs In/Hr cfs In/Hr cfs In/Hr cfs In/Hr cfs In/Hr cfs 1E 37.5 65.0 0.60 335 1.0 2.0 1700 2.8 300 6.0 14.0 14.0 5.4 121.1 6.6 148.4 7.4 167.3 8.5 191.4 9.6 216.8 10.1 226.2 2E 39.6 0.0 0.55 420 37.0 4.3 0 0 0 0 1.6 10.0 6.3 137.8 7.7 167.5 8.6 188.1 9.9 214.8 11.1 242.8 11.6 253.5 2P 32.5 90.0 0.90 325 2.0 1.0 400.0 4.8 1850 6.0 12.0 12.0 5.8 170.3 7.1 207.9 8.0 233.9 9.1 267.4 10.3 302.5 10.8 315.7 4E 5 8 0.55 750 3 2 0 0 0 0 6.3 10.0 6.3 17.4 7.7 21.2 8.6 23.7 9.9 27'.1 11.1 30.7 11.6 32.0 5P 2.3 10 0.55 600 3 2 0 0 150 6 5.4 10.0 6.3 8.0 7.7 9.7 8.6 10.9 9.9 12.5 11.1 14.1 11.6 14.7 Storm Drainage Area Calculations 1 11.0 90 0.90 350 .4 5 510 3 1750 6 8.9 10.0 6.3 62.7 7.7 76.2 8.6 85.6 9.9 97.7 11.1 110.5 11.6 115.3 2 6.09 90 0.90 300 14 13 360 13 0 0 0.8 10.0 6.3 34.7 7.7 42.2 8.6 47.3 9.9 54.1 11.1 61.1 11.6 63.8 -3 0.4§ 100 0.90 120 1.5 4 O· 0 0 0 0.5 10.0 6.3 2.6 7.7 3.1 8.6. 3.5 9.9 4.0 11.1 4.5 11.6 4.7 4 3.13 90 0.90 50 1 2 600 8 0 0 1.7 10.0 6.3 17.8 7.7 21.7 8.6 24.3 9.9 27.8 11.1 31.4 11.6 32.8 5 1.87 90 0.90 300 5 6 0 0 0 0 0.8 10.0 6.3 10.6 7.7 12.9 8.6 14.5 9.9 16.6 11.1 18.8 11.6 19.6 6 1.05 90 0.90 150 3 6 0 0 0 0 0.4 10.0 6.3 6.0 7.7 7.3 8.6 8.2 9.9 9.3 11.1 10.5 11.6 11.0 ·7 2.5. -85. 0.85 300 ~4 .6. o __ ... _. 0. 0. 0 ~0 .. 8 ~10.0 -6.3 13k 7.7 16.3 8.6 18.3 9.9 21.0 11.1 23.7 11.6 24.7 8 0.75 90 0.90 240 2 6 0 0 0 0 0.7 10.0 6.3 4.3 7.7 5.2 8.6 5.8 9.9 6.7 11.1 7.5 11.6 7.9 9 1.44 90 0.90 140 2 6 0 0 0 0 0.4 10.0 6.3 8.2 7.7 10.0 8.6 11.2 9.9 12.8 11.1 14.4 11.6 15.1 10 1.05 90 0.90 360 3.5 6 0 0 0 0 1.0 10.0 6.3 6.0 7.7 7.3 8.6 8.2 9.9 9.3 11.1 10.5 11.6 11.0 11 0.49 90 0.90 175 3 6 0 0 0 0 0.5 10.0 6.3 2.8 .7.7 3-4. 8.6. 3.8. 9.9 4.3. 11.1 4.9. 11.6 .. 5.1 12 0.76 100 0.90 200 1.5 6 0 0 0 0 0.6 10.0 6.3 4.3 7.7 5.3 8.6 5.9 9.9 6.7 11.1 7.6 11.6 8.0 13 1.78 90 0.90 240 2 6 0 0 0 0 0.7 10.0 6.3 10.1 7.7 12.3 8.6 13.8 9.9 15.8 11.1 17.9 11.6 18.6 14 0.29 90 0.90 240 2 6 0 0 0 0 0.7 10.0 6.3 1.7 7.7 2.0 8.6 2.3 9.9 2.6 11.1 2.9 11.6 3.0 15 0.3 100 0.90 180 2 6 0 0 0 0 0.5 10.0 6.3 1.7 7.7 2.1 8.6 2.3 9.9 2.7 11.1 3.0 11.6 3.1 16 0.09 100 0.90 80 1.5 6 0 0 0 0 0.2 10.0 6.3 0.5 7.7 0.6 8.6 0.7 9.9 0.8 11.1 0.9 11.6 0.9 17 1.18 100 0.90 240 2 6 0 0 0 0 0.7 10.0 6.3 6.7 7.7 8.2 8.6 9.2 9.9 10.5 11.1 11.8 11.6 12.4 L-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~BURY+PARTNERS~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~----' Label Upstream Upstream Inlet Inlet Area CA (acres) (acres ) P-1 37 .50 22 .50 'P-2 2.:5 0 2 .12 P-5 0.4 9 0.44 P-6 1 .78 1 .60 P-4 0 .2 9 0 .26 T it le : HD-Coll ege Station j :\048 \030 \publ ic dra in .stm 09/03/02 09 :30 :55 AM •• • ••••••••••••• Scenario: Base Pipe Report Upstream Calculated System Total Length Constructed Section Manning! Full Upstream Downstream Hydraulic Hydraulic System CA Intensity System (ft) Slope Size n Capacity Invert Invert Grade Grade (a c res ) (in/hr) Flow (ft/ft) (cfs) Elevation Elevation Line Out Line In (cfs) (ft) (ft) (ft) (ft) 22 .50 10.05 228 .01 166 .80 0 .005036 60 inch 0 .014 171.61 265 .29 264.45 274 .18 275 .66 24.6 3--9 .97 247.58 501 .00 0.004990 so inch O.D1 4 '~1 70 .83 26.iil .45 26 .95 268 .93 2 74 .18 25 .07 9.76 246.67 127 .72 0 .005011 60 inch 0 .014 171 .18 261 .95 261 .31 267 .60 268 .93 26 .67 9 .71 261.03 200.30 0 .004993 60inch 0 .0 14 170 .87 261 .31 260.31 265 .26 267 .60 26 .93 9 .63 261 .51 28 .00 0 .005000 60 inch 0.014 171 .00 260.31 260.17 264 .66 265.26 /Oo ~rz_. S fo rVV> Bury & Partners © Haestad Methods, Inc. 37 Brookside Road Waterbury , CT 06708 USA +1-203-755-1666 Project Eng ineer: BPI User StormCAD v4 .1.1 [4 .2014] Page 1 of 1 ((~ COLLEGl STATION FOR OFFICE USE ONLY P&Z CASE NO.: 03 {;? /..p(p DATE SUBMITTED: /O-:J D-0 ~ [).) () 3gt{- SITE PLAN APP LICATION MINIMUM SUBMITTAL REQUIREMENTS Site plan application completed in full. $200 .00 Application Fee. $200.00 Development Permit Application Fee . $600 .00 Public Infrastructure Inspection Fee if applicable. (This fee is payable if construction of a public waterline, sewerline , sidewalk, street or drainage facilities is involved .) Ten (10) folded copies of site plan . A copy of the attached site plan checklist with all items checked off or a brief explanation as to why they are not checked off. Parkland Dedication requirement approved by the Parks & Recreat ion Board , please provide proof of approval (if applicable). NAMEOFPROJECT~C=h~i c~k=e~n=E~xo~r=e=ss~-------------------------- ADDRESS 800 Earl Rudder Freeway LEGAL DESCRIPTION _ _,,L=ot"'-"'2=R_,_,E=._,,B=lo=c=k_,1'-G=a=t=ew'"'"=ayi-=S=ub=d'""iv'"""is..,o""'n'--------------------- APPLICANT (Primary Con tact for the Project): Name Veron ia Morgan /Mitchell & Morgan , LLP E-Ma il -~v .... @""'m~itc~h=e=lla=n=d""'m=o"'"'rg""'a~n"""'.c=o""'"m,,__ __ _ Street Address 511 University Drive East. Su ite 204 City Colleg e Station State _T~X"--------Zip Code 77840 PhoneNumber __ __.,{~97~9~)_,,2=6~0-~6~96~3~------Fax Number (979) 260-3564 PROPERTY OWNER 'S INFORMATION : Name Clayton W . Rhoades E-Mail claytonrhoades@hotmail .com Street Address __ 8=0~0~E=a=r~I R~u=d~d=e~r ~Fr~e=e~w=ay,__ ________________________ _ TX City __ C=o=l=le~g ... e_,.S=ta=ti .... o.._.n ________ State ---'-'-'-----Zip Code 77840 PhoneNumber __ ~{9~7~9~)~73~1~-~18=9~4 _______ _ Fax Number (979) 731-1894 ARCHITECT OR ENGINEER 'S INFORMATION : Name ____ _,,S=a~m=e~a=s~A~o~o=l ic=a=n~t _________ _ E-Ma il Street Address------------------------------------ City--------------State _______ _ Zip Code Phone Number _____________ ~ Fax Number OTHER CONTACTS (Please specify type of contact, i.e . proj ect manager , potential buyer, local contact , etc.) Name _ _,L=a~rrvu....:W~e=a=t~he=r~ly _____________ _ E-Mail Larrv@ ldwandassoc.com Street Address 6813 Franwood Terrance City Fort Worth Phone Number (817) 457-1954 Site Pl an.DO C 0 8/01/02 State TX Zip Code _ __,7_,,6:....:.1"""12,.__ ____ _ FaxNumbe r ---'-'(8~1~7~)~4~57~-~1~9~54-'----------- 1 of 3 CURRENTZONING_--=C-~1~w~/~O~-V""----------------------­ PRESENTUSEOF PROPERTY_~va=c=a~nt=---------------------~ PROPOSED USE OF PROPERTY ---r-"'e.;;;_st=a=u.o....=ra"'-n'-'-t -'-'-w-'-1 =dr-'-iv'-=e __ -t""""'h"'"""ru"----------------- VARIANCE(S) REQUESTED AND REASON(S) ---'-n'--"o-'-'-ne""------------------ #OF PARKING SPACES REQUIRED 23 #OF PARKING SPACES PROVIDED 23 --------~--- MUL Tl-FAMILY RESIDENTIAL PARKLAND DEDICATION tal Acreage __ #of Housi g Units __ Flo dplain Acreage __ ~1-t-A-ffl icoJJJe arks Board COMMERCIAL Total Acreage .586 acres Building Square Feet 2325 sf Floodplain Acreage " 0~ l/C(PS NOTE: Parkland Dedication fee is due prior to the issuance of a Building Permit. licant has prepared this application and certifies that the facts stated herein and exhibits attached re true and correct. SITE PLAN CHECKLIST Site Plan .DOC 08/01102 Date 2 of 3 "'9J 4 . ~ 5 . "e:i 6 . "0 7 . "(a ~ ~A "¥] "'eJ SUBMIT APPLICATION AND THIS LIST CHECKED OFF WITH 10 FOLDED COPIES OF SITE PLAN FOR REVIEW SITE PLAN MINIMUM REQUIREMENTS (ALL CITY ORDINANCES MUST BE MET) INCLUDING BUT NOT LIMITED TO THE FOLLOWING: Sheet size -24" x 36" (minimum). A key map (not necessarily to scale). Title block to include: Name, address, location, and legal description Name, address, and telephone number of applicant Name, address, and telephone number of developer/owner (if differs from applicant) Name, address, and telephone number of architect/engineer (if differs from applicant) Date of submittal Total site area North arrow. Scale should be largest standard engineering scale possible on sheet. Ownership and current zoning of parcel and all abutting parcels . Existing locations of the following on or adjacent to the subject site: Streets and sidewalks (R.O.W.). Driveways (opposite and adjacent per Section 7.3 of the Unified Development Ordinance). Buildings. Water courses. Show all easements clearly designating as existing and type (utility, access, etc.). 100 yr. floodplain and floodway (if applicable) on or adjacent to the proposed project site, note if there is none on the site. Utilities (noting size and designate as existing) within or adjacent to the proposed site, including building transformer locations, above ground and underground service connections to buildings , and drainage inlets. Meter locations. Topography (2' max or spot elevations) and other pertinent drainage information . (If plan has too much information, show drainage on separate sheet.) Proposed location, type and dimensions of the following.: Phasing. Each phase must be able to stand alone to meet ordinance requirements . The gross square footage of all buildings and structures and the proposed use of each. If different uses are to be located in a single building, show the location and size of the uses within the building . Building separation is a minimum of 15 feet w/o additional fire protection . Setbacks . Show building setbacks as outlined in the Unified Development Ordinance, Article 5. Off-Street parking areas with parking spaces drawn, tabulated, and dimensioned . Minimum parking space is 9' x 20', or on a perimeter row 9' x 18' with a 2' overhang . Designate number of parking spaces required by ordinance and provided by proposal. Handicap parking spaces. SITE PLAN CHECKLIST SITECK 06/17/03 I of3 Parking Is lands . Raised landscape islands, (6 " raised curb) a minimum of 180 sq . ft. are required at both ends of every parking row (greenspace· area contiguous to the end island maybe applied toward the required 180 sq . ft .). Additibnally, 180 sq . ft . of landscaping for every 15 interior parking spaces must be provided . All required islands must be landscaped or set with decorative pavers, or stamped dyed concrete or dther decorative materials as approved . Drives . Minimum drive aisle width . Curb cuts . For each proposed curb cut (including driveways, streets , alleys , etc.) locate existing curb cuts on the same opposite side of the street to determine separation distances between existing and proposed ~urb cuts . Indicate driveway throat length as measured in the Unified Development Ord i nance , Section 7 .3 Access Management and Circulation . "-~A Security gates (show swing path and design specs with colors). . '\Zl Sidewalks (both public and private). S idewalks are req u ired at time of development if property -pe~ !As, t has frontage on a street shown on the Sidewalk Master Plan or if the review staff determines r<v1ewern h . r~i.:.11'<'. t e necessity . ~ Medians . Show any and all traffic medians to be constructed on site . \o A fifteen foot parking setback from R.O.W. to curb of parking lot is required . Pavement may encroach into this 15' setback by up to 7 contiguous parking spaces . A double parking island (360 square feet) must be provided between each groJp of seven spaces . In no case may the pavement be less than 6' from the property line . NOTE: EJ/A Common open spaces sites Loading docks Detention ponds Guardrails Retaining walls All required and other types of fences (a 6' privacy fence is required between industrial/commercial and residential developments as well as between multi-family and single family developments). Sites for solid waste containers with screening . Locatiohs of dumpsters are accessible but not visible from streets or residential areas . Gates are discouraged and visual screening is requ ired . (Minimum 12 x 12 pad required .) Show all easements clearly designating as proposed and type (utility, access, etc.). If dedicated by separate instrument list by volume and page . Utilities (noting size and designate as proposed) within or adjacent to the proposed site , including building transformer locations, above ground and underground service connections to buildings . Meter locations (must be located in public R.O .W . or public utility easement.). Proposed grading (1' max for proposed or spot elevations) and other pertinent drainage information. (If plan has too much information , show drainage on separate sheet.) Show proposed and existing fire hydrants . Fire hydrant ~ must be located on the same side of a major street as a project, and shall be in a location approved by the City Engineer. Any structure in any zoning district other than R-1, R-1A, or R-2 must be within 300 feet of a fire hydrant as measured along a public street, highway or designated fire lane. WA Show fire department connections . FDC's should be within 150' of the fire hydrant. In no case shall they be any further than 300' apart, and they shall Be accessible from the parking lot without be ing blocked by parked cars or a structure . 9 . Show fire lanes . Fire lanes a minimum of 20 feet in width . with a minimum height clearance of 14 feet must be established if any portion of the proposed st(ucture is more than 150 feet from the curb line or pavement edge of a public street or highway. Fire hydrants must be operable and accepted by the City; and drives must have an all weather surface as defined in the Zoning Ordinance Section 9 before a building permit can be issued . Will building be sprinkled? Yes 0 No~ If the decision to sprinkle is made after the site plan has been approved , then the plan must be resubmitted. SITE PLAN CHECKLIST SITECK 06/17/03 2 of3 rMIA 10. WA &"A "o 11 . 12 . ~ 'ii ~ ~19.A mA ~IA ij;lfA 13. 14. 15. 16. 17. 18. 19. 20. NOTE: Wheelstops may be required when cars overhang onto property not owned by the applicant or where there may be conflict with hand icap accessible routes or above ground utilities , signs or other conflicts . Show curb and pavement detai l. A 6" raised curb is required around all edges of all parts of all paved areas without exception . (To include island , planting areas, access ways, dumpster locations, utility pads, etc.) Curb details may be found in the Section 7 .2 of the Unified Development Ordinance and alternatives to those standards must be approved by the C ity Engineer. No exception will be made for areas designated as "reserved for future parking ". Landscape plans as requ i red in Sect ion 7 .5 of the Unified Development Ord inance . The landscaping plan can be shown on a separate sheet if too much information is on the original site plan . If requesting protected tree points, then those trees need to be shown appropriately barricaded on the landscape plan . Attempt to reduce or eliminate plantings in easements . Include information on the plans such as : required point calculations additional streetscape points required . Streetscape compliance is required on all streets . calculations for# of street trees requ ired and proposed (proposed street tree points will accrue toward total landscaping points .) proposed new plantings with points earned proposed locations of new plantings screening of parking lots screening of dumpsters, detention ponds, transformers, A/C units, loading docks , propane tanks, utility demarcation point on buildings, or other areas potentially visually offensive . existing landscaping to remain show existing trees to be barricaded and barricade plan. Protected points will only be awarded if barricades are up before the first development permit is issued. Buffer as required in Section 7.6 of the U,nified Development Ordinance . Show irrigation system plan . (or provide note on how irrigation system requirement will be met prior to issuance of C.O.) All plans must include irrigation systems for landscaping . Irrigation meters are separate from the regular water systems for buildings and will be sized by city according to irrigation demand submitted by applicant and must include backflow prevention protection . Is there any landscaping in TxDOT R.O .W.? If yes , then TxDOT permit must be submitted . Will there be any utilities in TxDOT R.O.W.? If yes,-then TxDOT permit must be submitted. Will there be access from a TxDOT R.O.W.? If yes, then TxDOT permit must be submitted . Yes 0 No'\:i Yes 0 No~ Yes 0 No \u The total number of multi-family buildings and units to be constructed on the proposed project site. The density of dwelling units per acre of the proposed project. Provide a water and sanitary sewer legend to include water demands (minimum , maximum and average demands in gallons per minute) and sewer loadings (maximum demands in gallons per day). Are there impact fees associated with this development? Yes 0 No\i Signs are to be permitted separately . SITE PLAN CHECK.LIST SITECK 06/17/03 3 of3 _ P.O. Box 11028 College Station, TX 77842 10 October 2003 Gateway Fuels, LLC Attn: Drew Congleton 167 Monterrey Road Montgomery, Texas 77356 RE: Use of solid waste container agreement Dear Mr. Congleton, The purpose of this letter is to facilitate an agreement for Chicken Express of College Station to use the solid waste container located on the property at Gateway Fuels, LLC conven~ence store at the comer of Earl Rudder Freeway and University Drive. As per a phone conversation with Pete in the City of College Station Sanitation Department on 13 August 2003, upon adding a second dumpster to the existing enclosure, the waste created by Chicken Express would not exceed the limits set by the city. Let this document show that both parties have agreed to this arrangement and will settle on the proper compensation for the use of this container at a later date. Signed, Clayton W. Rhoades Chicken Express of College Station P.O. box 11028 College Station, TX 77842 Drew Congleton Gateway Fuels, LLC 167 Monterrey Road Montgomery, TX 77356